JP2001106563A - Lightweight calcium silicate board and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lightweight calcium silicate board that is lightweight and excellent in executing work and to provide a manufacturing method of the board. SOLUTION: A raw material for this board is prepared by blending an inorganic hardening agent, filler, an inorganic weight saving material and a reinforcing fiber so that the raw material contains over 50 wt.% and not more than 70 wt.% calcium sulfate dihydrate based on the 100 wt.% raw material. The raw material thus prepared is made into slurry, from which a sheet is then manufactured. The board prepared by using the sheets is subjected to hydrothermal synthesis to obtain the objective board having not less than 0.6 and less than 0.9 specific gravity, not less than 8 N/mm2 bending strength and not more than 45 N/mm needle penetration value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightweight calcium silicate plate which is lightweight and has good workability and a method for producing the same.

[0002]

2. Description of the Related Art Calcium silicate plates are widely used for interiors such as partition walls and ceilings and exteriors such as outer walls and eave ceilings because they are lightweight and nonflammable. Calcium silicate plates are not directly cracked or nailed at the time of installation, because they are directly screwed or nailed.However, commercially available calcium silicate plates are not necessarily required for workability such as screwing. Not satisfied. Further, there is a demand for further improvement in workability such as reduction of noise at the time of work, improvement of work efficiency, and reduction of impact force of screwing of a worker. As one of the improvement measures, Japanese Unexamined Patent Publication No. 5-155650 discloses a method in which 3 to 15% by weight of inorganic fine particles such as gypsum and talc are blended, the compression fracture strain is 8.0 × 10 ⁻² or more, and the Brinell hardness is 1.
A calcium silicate plate characterized by a ratio of 0 to 4.0 has been proposed.

[0003] On the other hand, with respect to the amount of gypsum to be added to a calcium silicate plate, Japanese Patent No. 2,583,186 discloses that as a method for preventing steam rupture, 10 to 50% by weight of gypsum is added. The preferred addition ratio of gypsum dihydrate is 20 to 30% by weight, and the addition of a large amount exceeding 50% by weight is not generally preferred since the adverse effect of greatly reducing the strength becomes remarkable. The mixing of 50% or more of water gypsum has not been performed.

[0004]

As the construction method is being rationalized, the efficiency of the workability of the calcium silicate plate as the final finishing material is required. Since the calcium silicate plate is constructed by hand, it is required to be lightweight and have excellent workability such as cutting and screwing during construction as basic performance. INDUSTRIAL APPLICABILITY The present invention has sufficient strength as an interior material, an inner wall, a ceiling or an eave ceiling material, and significantly improves the workability of screwing and the like, reduces noise at the time of construction, increases work efficiency, and improves work efficiency. It is an object of the present invention to provide a calcium silicate plate which can reduce the impact of screwing by a user and does not cause cracking or chipping even when directly screwed.

[0005]

Means for Solving the Problems In order to achieve the above object, as a result of intensive research, from the viewpoint of formulation and production,
The inventors have found a solution and completed the present invention. In addition, there has been no appropriate method to evaluate workability,
This time, when we introduced a test method called nail press-in, we found that there was a high degree of correlation between the nail press-in value and cracks and chips at the time of construction. The present inventors have found a peculiar phenomenon in the compounded calcium silicate plate and have reached the present invention. The percentages by weight shown below are percentages by inward division.

According to the present invention, there is provided a calcium silicate plate obtained by forming a raw material slurry containing an inorganic hardening material, a filler, an inorganic lightening material and a reinforcing fiber, and hydrothermally synthesizing the formed plate. In terms of weight%, gypsum dihydrate is added to the raw material in an amount of more than 50% by weight to 70% by weight, the specific gravity is 0.6 or more and less than 0.9, the bending strength is 8 N / mm ² or more, and the nail is pressed. This is a lightweight calcium silicate board having a value of 45 N / mm or less.

Further, a calcium silicate obtained by forming a raw material slurry containing an inorganic hardening material, a filler, an inorganic lightening material (hereinafter, referred to as a lightening material) and reinforcing fibers, and hydrothermally synthesizing the obtained sheet. In the board, when the above-mentioned raw material is set to 100% by weight, gypsum dihydrate is added to the raw material in an amount of more than 50% by weight and 70% by weight or less, and the inorganic weight-reducing material is 1%.
It is a lightweight calcium silicate board characterized by containing ２０20% by weight.

Further, a raw material slurry containing an inorganic hardening material, a filler, and a reinforcing fiber as an inorganic lightening material is formed into a paper,
In the method for producing a calcium silicate plate obtained by hydrothermally synthesizing the papermaking plate, the gypsum dihydrate is blended in an amount of more than 50% by weight and 70% by weight or less in 100% by weight of the raw material.
A slurry containing 1 to 20% by weight of a lightening material is formed,
It is press-formed with a surface press pressure of ^{2 to} 10 N / mm ² , and is hydrothermally synthesized to have a specific gravity of 0.6 or more and less than 0.9, a bending strength of 8 N / mm ² or more, and a nail penetration value of 45 N / m.
m or less, which is a method for producing a lightweight calcium silicate plate.

As the inorganic hardening material, various cements such as Portland cement and mixed cement, siliceous raw materials and calcareous raw materials can be used. As the fibers, natural fibers such as pulp, glass fibers, rock wool, ceramics wool, inorganic fibers such as carbon fibers, and synthetic fibers such as polyamide, polypropylene, polyvinyl alcohol, polyester, polyethylene, and acrylic can be used. From those fibers, papermaking properties,
It is appropriately selected and used from the viewpoint of the moisture content of the raw plate and the properties of the product, and the amount used is 1 to 10% by weight.

As a filler, gypsum dihydrate can be blended in an amount of more than 50% by weight to 70% by weight. If necessary, limestone, anhydrous gypsum, wollastonite, talc, slag, fly ash, mica, etc.
It can be used in combination with up to 10% by weight. Diatomaceous earth, lime-silica-based hydrothermal compound
One or more species can be used. The amount of lightening material used is 1 to
20% by weight.

The lightweight calcium silicate plate of the present invention is produced by a method such as round netting, long netting, flow-on or pressure molding. The steps are described below. An inorganic hardening material, a filler, a lightening material and fibers are mixed at a predetermined mixing ratio, and 3 to 15 times the amount of water is added to a raw material containing this mixture as a main component and stirred with a pulper to form a slurry. After the slurry is homogenized, the slurry is formed by a paper machine such as a round net, a long net or flow-on, and a thin film is wound up by a making roll to produce a green sheet.
The thickness is adjusted to about 4 to 20 mm. Alternatively, there may be a case where the paper is made to a predetermined thickness without using a making roll.

Pressing is performed on the surface of the formed green sheet. The surface press presses and holds the upper and lower surfaces of a green sheet by sandwiching the upper and lower surfaces with smooth polished iron plates. The holding pressure varies depending on the amount of the dihydrate gypsum and the weight-reducing material.
10 N / mm ² is preferred. The green sheet is subjected to steam curing at a temperature of 30 to 80 ° C. for 1 to 10 hours after laying. Thereafter, hydrothermal synthesis is performed by an autoclave.
Autoclave temperature is about 5 to 15 at about 160 to 180 ° C.
Hours or more.

In the present invention, a nail press-fit test was performed as a test method representing workability represented by screwing. The nail press-fitting test method is as follows: a test piece cut into 100 mm x 100 mm is dried for 24 hours with a drier kept at 60 ± 3 ° C, and the test piece 2 is set in the bending tester 1 using the test equipment shown in FIG. And iron round nail N32 (JIS A5508) (length 32
mm, φ 1.90 mm) 3 is set on a test piece, and a load test is performed at an average load speed such that a time until the maximum load is reached is about 30 to 60 seconds. Measure the maximum load. The nail penetration value is the maximum load divided by the thickness of the test piece. In FIG. 1, reference numeral 4 denotes a nail guide fitting, 5 denotes a washer, 6 denotes a nail pusher, 7 denotes a nail pusher support, 8 denotes a cedar material, and 9 denotes an iron plate. As shown in FIG. 2, the nail guide fitting 4 is arranged at the corner of the test piece 2 such that the nail press-fitting position is 30 mm from each end face of the corner. In addition, a one-touch screw test was performed on a metal base using the same plate as the test piece that had been subjected to the nail press-fit test, and the number of cracks and chips and the nail press-fit value were measured. An experiment was performed on the relationship. In the one-touch screw test, ten screws were hit at a position 25 mm from the edge of the plate, and the number of cracks or chips was expressed.

FIG. 3 shows an experimental example. Nail press-fit value and 3 '×
A high degree of correlation was found between cracking and chipping in the one-touch screw test using a 3 'plate, and the nail press-in value was 45N.
If it exceeds / mm, cracks occur, and the number increases as the value increases. From the above, there is a high degree of relationship between the nail press-in value and the workability by screwing, and it is considered that the nail press-in value is a substitute characteristic of the screwing workability.

Next, a raw material slurry containing an inorganic hardening material, a filler, an inorganic lightening material, and a reinforcing fiber is vertically 300
The resulting mortar was placed in a simple filtration mortar molding machine equipped with a mold frame of 300 mm × 300 mm in width and subjected to surface pressing at a predetermined surface pressure to form mortar. After steam curing at 60 ° C for 4 hours,
About calcium silicate mortar board which performed autoclave curing at 175 degreeC for 12 hours, the experiment was performed about the relationship between the compounding amount of gypsum dihydrate, bending strength, and nail injection. FIG. 4 shows an experimental example. Although not shown, since a high degree of correlation is observed between the specific gravity of the plate, the bending strength, and the press-fitting of the nail, in the present experimental example, the specific gravity of the plate was changed to 0.80 ± by changing the surface pressing pressure. It controlled so that it might be set to 0.01.

As can be seen from FIG. 4, the bending strength is 8 N /
maintaining mm ² or more, gypsum amounts to nail pressed value is less 45N / mm is 55 to 70 wt%. In this range, the decrease in bending strength is small, but the rate of decrease in nail press-in value is large. That is, if the amount of gypsum is 55 to 70%,
It was found that it was a peculiar range in which the nail press-in value was small even though the bending strength was maintained.

Although such a peculiar phenomenon has not been sufficiently elucidated, when gypsum is blended and autoclaved at 160 ° C. or higher, most of the gypsum is dehydrated by anhydrous gypsum. Lighter weight and lower specific gravity.
Therefore, increasing the surface pressing pressure on the green sheet to maintain the specific gravity reduces the large pore size without changing the total pore size due to the interaction with the inorganic hardening material, lightening material, filler and fiber, and apparently It is thought that it will be dense packing.
Further, it is sufficient that the amount of the hardening material exhibiting the strength is not less than a certain amount, and it is presumed that the bending strength is maintained by both of them. On the other hand, the nail penetration value is improved with a decrease in the amount of hardening material, that is, by incorporating 55 to 70% by weight of gypsum. For such a reason, it is considered that the above-described peculiar phenomenon occurred.

[0018]

The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. [Examples 1 to 3] In this example, calcium silicate plates were manufactured based on the raw material blending and manufacturing conditions shown in Table 1.
Cylinder diameter 1000 mm x length 1717 mm, paper is formed by a 4-bat round netting machine, wound up into four layers by a making roll, 6 mm thick, 910 x 1820 mm
A green sheet of a size was obtained. Predetermined boost speed,
A surface press was performed at the holding pressure shown in Table 1 at 175 ° C., 15
After autoclaving for a time, the plate was dried and tested, and the results are shown in Table 2.

[0019]

[Table 1]

[0020]

[Table 2]

[Comparative Examples 1 to 7] Table 1
Table 2 shows the test results of the plates manufactured based on the raw material composition and the manufacturing conditions shown in Table 2. Ordinary cement: Brain value 3,300 cm ² / g, 22.2% by weight of silicon dioxide, 63.0% by weight of calcium oxide, 5.2% by weight of aluminum oxide, 4.1% by weight of gypsum dihydrate (1% by weight of sulfur trioxide). (Calculated from 9% by weight) Powdered silica: Chichibu Mining Co., Ltd., purity: 95.0% by weight, Blaine value: 3,600 cm ² / g Quick lime: Okutama Kogyo Co., Ltd., purity: 95.5% by weight, particle size: 150% through 92.0% Limestone: Arimitsu Mining's product. Blaine 3500 cm ² / g Gypsum: Excreted gypsum. Blaine 3,400 cm ² / g Hydrothermal synthesis slurry: calcareous / siliceous ratio 0.90, solid / water ratio 0.10 Press pressure: N / mm ² Pressurization time: time until press is held (minute-hold) Is 4 minutes) Specific gravity: Measured according to JIS A5430 Flexural strength: Measured according to JIS A5430 (N / mm ² )

The calcium silicate plate of the above example had the same bending strength as the conventional product, but the nail press-in value could be greatly reduced.

[0023]

According to the method for producing a calcium silicate plate of the present invention, a calcium silicate raw material slurry is prepared by mixing 55 to 70% by weight of gypsum dihydrate in an inorganic hardening material, an inorganic lightening material and a reinforcing fiber. The light green calcium silicate plate obtained by applying an appropriate surface pressing pressure to the obtained green sheet and autoclaving at 160 ° C. or higher has a bending strength of 8 N /
When the thickness was ² mm or more, the nail penetration value was much smaller than that of the conventional calcium silicate plate, and the workability of cutting, screwing, nailing, and the like was much improved compared to the conventional product. As a result, cracking and chipping at the time of one-touch screw driving can be eliminated, construction efficiency can be increased, and the impact of screw driving by an operator can be reduced.

[Brief description of the drawings]

FIG. 1 is an elevational view, partially in section, of a testing machine for measuring nail penetration values.

FIG. 2 is a plan view showing a relationship between a test piece and a nail guide.

FIG. 3 is a table showing experimental results obtained by the tester shown in FIG. 1;

FIG. 4 is a chart showing the relationship between the amount of gypsum and the nail penetration value.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Test machine 2 Test piece 3 Nail 4 Nail guide 5 Washer 6 Nail pusher

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C04B 14:08) C04B 14:08) 111: 30 111: 30 (72) Inventor Eiji Kawaguchi 2-chome, Shiba-Daimon, Minato-ku, Tokyo No.12 No.10 Asano Slate Co., Ltd. F term (reference) 4G012 PA04 PA14 PA22 PC11 PC12 PD03 RA03 RA05

Claims (3)

[Claims] 1. A calcium silicate plate obtained by forming a raw material slurry containing an inorganic hardening material, a filler, an inorganic lightening material and a reinforcing fiber, and hydrothermally synthesizing the formed paper plate to obtain 100 wt. %, The amount of gypsum is more than 50% by weight and not more than 70% by weight, and the specific gravity is 0.6 or more and less than 0.9, and the bending strength is 8 N / m.
m ² or more, light-weight calcium silicate board nail pressed value is equal to or less than 45N / mm. 2. The method according to claim 1, wherein 20% by weight or less of an inorganic lightening material is added to 100% by weight of the raw material.
The lightweight calcium silicate plate according to 1. 3. A method for producing a calcium silicate plate obtained by papermaking a raw material slurry containing an inorganic hardening material, a filler, an inorganic lightening material and a reinforcing fiber, and hydrothermally synthesizing the papermaking plate. A slurry containing more than 50% by weight of gypsum dihydrate and not more than 70% by weight of 100% by weight, and further, not more than 20% by weight of an inorganic lightening material is formed, and a surface press pressure of ² to 10 N / mm ² is formed. The specific gravity is 0.6 or more and 0.9 by hydrothermal synthesis.
Less than, bending strength 8N / mm ² or more, nail press-fit value 45N /
mm or less, a method for producing a lightweight calcium silicate plate.